Subject: Re: Dual displays on a MAXINE
To: None <>
From: Jonathan Stone <>
List: port-pmax
Date: 05/27/1996 20:19:43
David Conran asks:

>Anyways .. I added the card, and it automatically assume the PMAG-JA is
>the new display (over the internal PMAG-DV)
>My question is ... how do I get the kernel to see both.
>I have gotten this working on a 5000/133 using a PMAG-JA and a PMAGB-BA
>But for some reason when adding another fb entry in the kernel, I get nothing

>From the context, this simply *has* to be under Ultrix. I'm not sure I
can help. Setting the "osconsole" variable to tell the PROM to use the
PMAG-DV *should* help. I'm not sure what the magic numbers are -- "3"
or "3/3", I suspect.

Ted Lemon replies:

>The NetBSD code that figures out which frame buffer to use as the
>console is set up to pretend that the XCFB isn't there if there's
>*any* other frame buffer installed.   There's currently no way around
>this other than hacking the source - probably in cpu_cons.c or
>something, but I can't remember for sure.

Yes,  but I can't see how David's question makes any sense in the context
a NetBSD/pmax kernel. However...

That's the right file. It sets up the Maxine's XCFB as console, if the
"osconsole" PROM variable is set to 3/3, and then calls functions in
pmax/tc/tc_subr.c to look for TC option framebuffers, and uses one as
console display (for rastercons) if found.

However, since NetBSD doesn't support the PMAG-JA (TX), the tc_subr.c
code is *not* going to use it.  I'm guessing David is perhaps trying to get
this to work on Ultrix, or perhaps on a machine that can boot either
Ultrix or NetBSD.

>BTW, it shouldn't be that hard to get the TX frame buffer driver going
>on X11R6 - my recollection is that the TX is just a 24-bit dumb frame
>buffer (that's why it's so bleedin' slow).   It might have SFB
>capability, but that wouldn't be taken advantage of.

Like, pretend it's a CFB but with truecolour instead of an 8-bit mask?
(is that what xdpyinfo says with the Ultrix server?)
Sounds like it should be a simple tweak to the X11R6{,.1} Xdec...